An electric vehicle uses electricity as a power source different from a gasoline vehicle or a diesel vehicle using gasoline or diesel, so it is an environment-friendly vehicle without emitting exhaust gases.
Since a conventional two-speed transmission for an electric vehicle needs a step of forcibly synchronizing speeds between an input shaft and an output shaft with a synchronizer ring or the like during shift from a first shift speed to a second shift speed, shift shock may occur so that a higher speed shift control performance is required in order to solve this problem. Also, since a transmission for an electric vehicle is driven by a motor which is driven by electricity which is the power source of an electric vehicle, it should be lightweight and needs to have a simplified structure.                Prior art document: Korea patent publication No. 10-2012-0055335        